Immunogenicity assay development and validation for biological therapy as exemplified by ustekinumab

The role of antidrug antibodies in ustekinumab therapy and the impact of methotrexate

OBJECTIVE

We investigated the impact of concomitant MTX on ustekinumab (UST) levels and antidrug antibody (ADA) formation in PsA and evaluated consequences in pharmacodynamics and pharmacokinetics.

METHODS

We conducted a post-hoc analysis on 112 PsA serum samples of subjects treated with open-label UST and either concomitant MTX (UST/MTX, n = 58) or placebo (UST/pbo, n = 54) obtained in a randomized (1:1), double-blind, multicentre trial. A validated antibody-binding-based multitiered testing was used to detect ADA and ADA with neutralizing capacity (nADA). The impact of MTX on UST immunogenicity was analysed by comparison of UST/pbo with UST/MTX cohorts at different time points. Patient- and disease-related predispositions for ADA formation were investigated with multiple linear regression analysis. Immunogenicity impact on pharmacokinetics, safety and efficacy was determined by cohort comparison between patients with and without ADA formation.

RESULTS

Over 52 weeks, 11 UST/pbo- and 19 UST/MTX-treated patients developed ADA (P > 0.05). In the UST/pbo cohort, the visit-dependent UST levels were in the range of 0.047 (0.05) -0.110 (0.07) µg/ml overall, and 0.037 (0.04)-0.091 (0.08) µg/ml in ADA-confirmed subjects. In UST/MTX-treated patients, the UST levels exhibited an intervisit variation in the range of 0.0502 (0.04)-0.106 (0.07) µg/ml overall and 0.029 (0.03)-0.097 (0.07) µg/ml in ADA positive subjects (P > 0.05). At week 52, ADA-confirmed patients did not differ significantly (P > 0.05) in safety or clinical outcomes from ADA-negative patients.

CONCLUSION

Concomitant MTX had no significant impact on UST immunogenicity. Furthermore, ADA formation was not associated with impairments in UST safety, efficacy or trough levels.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT03148860.

Methotrexate plus ustekinumab versus ustekinumab monotherapy in patients with active psoriatic arthritis (MUST): a randomised, multicentre, placebo-controlled, phase 3b, non-inferiority trial

BACKGROUND

The role of methotrexate in combination with biological agents in patients with psoriatic arthritis remains unclear. The MUST phase 3b trial aimed to compare the efficacy of ustekinumab plus placebo with ustekinumab plus methotrexate in patients with active psoriatic arthritis.

METHODS

In this investigator-initiated, randomised, multicentre, placebo-controlled, phase 3b non-inferiority trial done in 22 centres in Germany, patients with active psoriatic arthritis received open-label ustekinumab and were randomly assigned (1:1) to masked concomitant therapy with placebo or methotrexate (ongoing or new). The primary outcome was non-inferiority of mean Disease Activity Score-28 joints (DAS28) at week 24 for ustekinumab monotherapy (ustekinumab plus placebo) versus ustekinumab combination therapy (ustekinumab plus methotrexate), stratified by previous methotrexate treatment. The key secondary analysis was non-inferiority of DAS28 at week 52. The primary analysis was based on a stratified van Elteren test with an α of 2·5% and a non-inferiority margin of 12·5% by Mann-Whitney estimator. Adverse events and serious adverse events were assessed. This study is registered with ClinicalTrials.gov, NCT03148860.

FINDINGS

Between Jan 24, 2017, and April 12, 2021, 186 patients with active psoriatic arthritis were screened, of whom 173 (93%) patients were enrolled and randomly assigned (1:1) to receive concomitant methotrexate therapy (n=88) or placebo (n=85). 84 patients were receiving methotrexate at baseline, and 89 patients had no previous methotrexate treatment. 166 (96%) patients (87 in the ustekinumab plus methotrexate group and 79 in the ustekinumab plus placebo group) were included in the safety and efficacy analyses at week 24 (69 [42%] female; 97 [58%] male; mean age 48·2 years [SE 1·1]). Ustekinumab plus placebo was non-inferior to ustekinumab plus methotrexate in DAS28 at week 24 (2·9 [SD 1·31] vs 3·1 [1·42]); the stratified Mann-Whitney estimator for treatment comparison was 0·5426 (95% CI 0·4545-0·6307). Non-inferiority for ustekinumab plus placebo was also observed in DAS28 at week 52. Serious adverse events occurred in seven (9%) patients in the ustekinumab plus placebo group and eight (9%) patients in the ustekinumab plus methotrexate group. No specific serious adverse events affected more than one patient, and there were no deaths.

INTERPRETATION

Interleukin (IL)-12 and IL-23 inhibition with ustekinumab is an effective treatment for psoriatic arthritis independent of methotrexate use; concomitant methotrexate did not increase efficacy of ustekinumab (based on DAS28). On the basis of these data, there is no evidence to support the addition or maintainance of methotrexate when initiating ustekinumab in patients with active psoriatic arthritis.

FUNDING

Janssen Cilag.

Anti-TNF therapy and immunogenicity in inflammatory bowel diseases: a translational approach

Inflammatory bowel diseases are chronic illnesses that involve intestinal inflammation and are usually diagnosed as Crohn's disease or ulcerative colitis. As these diseases do not have a cure, the goal of treatment is to induce and maintain remission. Monoclonal antibodies have been recognized as the most advanced therapy to avoid complications and reduce the need for surgical approaches. However, although their effectiveness has been proven by several studies, they can trigger the immune system, induce the occurrence of immunogenicity, which may lead to the loss of response and treatment failure. The purpose of this review is to determine what are the main mechanisms involved in IBD; to assess the recommended treatments; to explore the mechanisms of immunogenicity. We also try to explain the detection and describe the existing advances that make possible the clinical application of these approaches.

Application of selected biosensor techniques in clinical diagnostics

INTRODUCTION

Examination of disease biomarkers mostly performed on crude materials, such as serum, meets some obstacles, resulting from sample complexity and the wide range of concentrations and sizes of the components. Techniques currently used in clinical diagnostics are usually time-consuming and expensive. The more sensitive and portable devices are needed for early diagnostics. Chemical sensors are devices that convert chemical information into parameters suitable for fast and precise processing and measurement.

AREA COVERED

We review the use of biosensors and their possible application in early diagnostics of some diseases like cancer or viral infections. We focus on different types of biorecognition and some technical modifications, lowering the limit of detection potentially attractive to medical practitioners.

EXPERT OPINION

Among the new diagnostic strategies, the use of biosensors is of increasing interest. In these techniques, the capture ligand interacts with the analyte of interest. Measuring interactions between partners in real time by surface plasmon resonance yields valuable information about kinetics and affinity in a short time and without labels. Importantly, the tendency in such techniques is to make biosensor devices smaller and the test results apparent with the naked eye, so they can be used in point-of-care medicine.

Is There a Role for Therapeutic Drug Monitoring in Patients with Hidradenitis Suppurativa on Tumor Necrosis Factor-α Inhibitors?

Tumor necrosis factor-α inhibitors, adalimumab and infliximab, are at the forefront of biologic therapy for the management of moderate-to-severe hidradenitis suppurativa, with adalimumab as currently the only approved medication for this condition. In treating patients, primary or secondary lack of response (also termed suboptimal response) is a major burden for both patients and healthcare systems and is a challenge with biologics in part owing to the development of anti-drug antibodies following treatment. To overcome this, therapeutic drug monitoring may be conducted proactively or reactively to a patient's suboptimal response guided by measurements of trough serum drug concentrations and levels of anti-drug antibodies. While strong evidence to support the utility of therapeutic drug monitoring exists in patients with inflammatory bowel disease, current information is limited in the context of hidradenitis suppurativa. We sought to summarize the available evidence and to present the role of therapeutic drug monitoring and other dose optimization strategies in improving clinical response in patients with hidradenitis suppurativa treated with tumor necrosis factor-α inhibitors.

Immunogenicity of biologic agents in rheumatology

Biologic agents have become a core component of therapeutic strategies for many inflammatory rheumatic diseases. However, perhaps reflecting the specificity and generally high affinity of biologic agents, these therapeutics have been used by rheumatologists with less consideration of their pharmacokinetics than that of conventional synthetic DMARDs. Immunogenicity was recognized as a potential limitation to the use of biologic agents at an early stage in their development, although regulatory guidance was relatively limited and assays to measure immunogenicity were less sophisticated than today. The advent of biosimilars has sparked a renewed interest in immunogenicity that has resulted in the development of increasingly sensitive assays, an enhanced appreciation of the pharmacokinetic consequences of immunogenicity and the development of comprehensive and specific guidance from regulatory authorities. As a result, rheumatologists have a greatly improved understanding of the field in general, including the factors responsible for immunogenicity, its potential clinical consequences and the implications for everyday treatment. In some specialties, immunogenicity testing is becoming a part of routine clinical management, but definitive evidence of its cost-effectiveness in rheumatology is awaited.

An update on serum biomarkers to assess axial spondyloarthritis and to guide treatment decision

Axial spondyloarthritis (axSpA) is a group of debilitating, chronic, rheumatic conditions characterized by inflammation and new bone formation, mainly involving the spine and the sacroiliac joints. The lack of biomarkers in axSpA is well known. Despite significant treatment advances in recent years thanks to the introduction of drugs with a new mode of action, such as new biologic and targeted synthetic disease-modifying antirheumatic drugs, no relevant improvement in the identification of disease biomarkers has been achieved. Common parameters, such as erythrocyte sedimentation rate and C-reactive protein, which are routinely used to measure systemic inflammation, are the sole markers available to date and are not adequate to assess disease activity in all patients. The aim of this study is to review the most promising serum biomarkers that may help treatment decision in axSpA via a proper assessment of disease activity and identification of negative prognostic factors.

Severe acute toxoplasmosis infection following ustekinumab treatment in a patient with psoriasis vulgaris

A 26-year-old man undergoing therapy with 45 mg ustekinumab (Stelara) for chronic psoriasis vulgaris was referred by his general practitioner to an infectious diseases department for fatigue, fever, night sweating, generalised lymphadenomegaly and unexplained weight loss. Physical examination revealed bilateral occipital, cervical, axillary and inguinal lymphadenomegalies in addition to splenomegaly. Preliminary investigation revealed elevated Plasmodium lactate dehydrogenase and an inversion of the CD4/CD8 ratio. Whole-body spiral CT scanning with and without contrast showed splenomegaly and highlighted supradiaphragmatic and subdiaphragmatic lymphadenopathies. A complete Infectious Disease Test Panel revealed high levels of anti-Toxoplasma gondii antibodies. Immunoglobulin G avidity was negative. Peripheral blood lymphocyte phenotyping was performed to exclude underlying lymphatic neoplasia. The diagnosis of severe acute toxoplasmosis infection in the setting of immune response modifiers was made. Ustekinumab was suspended indefinitely and the patient underwent monthly serological tests to monitor the immune response until all symptoms resolved and the serological testing was negative for Toxoplasma.